1. Field of the Invention
The present invention relates to a braking apparatus for braking rotation of a wheel of a wheelchair, handcart or other vehicle. More particularly, the invention relates to a braking apparatus for use with a wheel covered at its outer periphery with a tire which is formed of a rubber or other elastic material, wherein the braking apparatus includes a member that is brought into contact with the tire, for thereby braking rotation of the wheel.
2. Discussion of Related Art
Most of conventional braking apparatuses used for wheelchairs have been designed to completely inhibit movement of the wheelchair by locking wheels of the wheelchairs. In view of a recently increasing utilization of wheelchairs in various kinds of fields, there is proposed an improved braking apparatus, e.g., a braking apparatus which is additionally equipped with a mechanism for preventing a backward movement of a wheelchair in an upslope, as disclosed in JP-A-7-227408. However, the conventional braking apparatuses including the braking apparatus disclosed in the Japanese publication have complicated constructions, and do not have sufficiently high degree of durability and maneuverability. That is, the conventional braking apparatuses should be further improved to overcome these drawbacks. Conventional braking apparatuses used for other vehicles such as handcarts carrying a person or goods have the same drawbacks to be overcome.
It is therefore an object of the present invention to provide a braking apparatus which is improved in at least one of simplification of construction, service life and maneuverability.
The above object may be achieved according to any one of the following modes of the present invention, each of which is numbered like the appended claims and depends from the other mode or modes, where appropriate, to indicate and clarify possible combinations of elements or technical features. It is to be understood that the present invention is not limited to the technical features or any combinations thereof which will be described for illustrative purpose only. It is to be further understood that a plurality of elements or features included in any one of the following modes of the invention are not necessarily provided all together, and that the invention may be embodied without some of the elements or features described with respect to the same mode.
(1) A braking apparatus for braking a wheel of a vehicle, comprising:
a main body;
a cam which is supported by the main body such that the cam is rotatable about an axis thereof, and which has a cam surface whose distance from the axis changes as viewed in a circumferential direction of the cam;
a movable member which is held by the main body such that the movable member is movable relative to the main body, and which holds a cam follower portion engaging the cam surface, and a braking portion brought into contact with a tire of the wheel; and
an operating device which includes an operating member operable to be moved in first and second directions, and which rotates the cam in one of opposite directions in response to the movement of the operating member in the first direction, for thereby moving the movable member in a forward direction that causes the braking portion to be displaced toward the tire, and rotates the cam in the other of the opposite directions in response to the movement of the operating member in the second direction, for thereby moving the movable member in a reverse direction that is opposite to the forward direction.
When the operating member is operated to be moved in the first direction in the braking apparatus according to mode (1) of this invention, the cam is rotated in one of the opposite directions in response to the movement of the operating member in the first movement, and the movable member engaged at the cam follower portion with the cam surface is moved in the forward direction as a result of the rotation of the cam in the above-described one of the opposite directions, so that the braking portion of the movable member is forced against the tire of the wheel, whereby rotation of the wheel is braked. In this instance, the movable member is moved with a sufficiently large force owing to a boosting function provided by the cam surface of the cam. When the operating member is operated to be moved in the second direction in the present braking apparatus, the movable member is moved in the reverse direction as a result of the rotation of the cam in the other of the opposite directions, so that the braking portion is separated from the tire of the wheel. The mechanism used in the present braking apparatus for moving the movable member is simplified as described above, thereby making it possible to manufacture the braking apparatus in a reduced cost.
Where a grooved cam or other positive-return cam is used as the above-defined cam in the present braking apparatus, the movable member can be positively moved in the reverse direction as well as in the forward direction, by the movement of the operating member. Where a plate cam or other non-positive-return cam is used as the cam, a suitable device for returning or reversely moving the movable member is preferably provided in the present braking apparatus. The suitable device may be, for example, adapted to bias the movable member in the reveres direction whereby the movable member is moved in the reverse direction in response to the movement of the operating member in the second direction, for thereby releasing the engagement of the braking portion with the tire of the wheel.
(2) A braking apparatus according to mode (1), further comprising a reverse-movement preventing device which prevents the movement of the movable member in the reverse direction.
In the vehicle equipped with braking apparatus of this mode (2), even if an user or operator releases the operating member while the vehicle is being braked by the braking apparatus, the braking apparatus is held in its working state so that the vehicle keeps to be braked by the braking apparatus. Thus, this arrangement further improves the maneuverability of the braking apparatus.
(3) A braking apparatus according to mode (2), wherein the reverse-movement preventing device includes a positioning device which positions the movable member in a selected one of a plurality of predetermined positions relative to the main body, and holds the movable member in the selected position.
In the braking apparatus of this mode (3), the movable member is positioned and then held in a selected one of the plurality of positions, by the positioning device. The plurality of positions may be determined on the basis of an operating state of the braking apparatus. For example, where the plurality of positions consists of three positions (i.e., first, second, third positions), the three positions may be determined so as to respectively correspond to a braking state, a reverse-rotation inhibiting state and a non-working state of the braking apparatus. Described more specifically, the three positions may be determined such that (a) the braking apparatus is placed in the braking state in which the wheel is braked by the braking apparatus, when the movable member is positioned in the first position, (b) the braking apparatus is placed in the reverse-rotation inhibiting state in which reverse rotation of the wheel is inhibited or braked by the braking apparatus while forward rotation of the wheel is permitted, when the movable member is positioned in the second positioned, and (c) the braking apparatus is placed in the non-working state in which the wheel is not braked by the braking apparatus, when the movable member is positioned in the third position.
The three positions may be determined also on the basis of a working state of the braking apparatus, namely, on the basis of an amount of braking force applied to the wheel by the braking apparatus. In this case, the three positions may be determined so as to correspond to a strongly braking state, a moderately braking state and a slightly braking state of the braking apparatus, wherein respective three different braking forces are produced by the braking apparatus. Described more specifically, the three positions may be determined such that (a) the braking apparatus is placed in the strongly braking state in which the wheel is strongly braked by the braking apparatus, when the movable member is positioned in the first position, (b) the braking apparatus is placed in the moderately braking state in which the wheel is moderately braked by the braking apparatus, when the movable member is positioned in the second position, and (c) the braking apparatus is placed in the slightly braking state in which the wheel is slightly braked by the braking apparatus, when the movable member is positioned in the third position.
Thus, the arrangement of this mode (3) is effective to enable the user or operator of the vehicle to clearly recognize the operating or working state of the braking apparatus. It is to be understood that the plurality of positions may be determined on the basis of not only one of the above-described operating and working states of the braking apparatus but also the combination of the operating and working states of the braking apparatus. In this case, the above-described plurality of positions may consist of more than three, for example, five, such that the five positions are determined so as to correspond to the strongly braking state, the moderately braking state, the slightly braking state, the reverse-movement inhibiting state and the non-working state of the braking apparatus.
(4) A braking apparatus according to mode (3), wherein the positioning device includes a first engaging portion which is provided in one of the cam surface and the cam follower portion, and a second engaging portion which is provided in the other of the cam surface and the cam follower portion and which is engageable with the first engaging portion, and wherein one of the first and second engaging portions consists of a plurality of engagers which are selectively brought into engagement with the other of the first and second engaging portions.
In the braking apparatus of this mode (4), the cam is positioned and then held in a selected one of a plurality of angular positions, by the engagement of the first and second engaging portions, so that the movable member is held in one of the above-described plurality of predetermined positions which corresponds to the selected one of the angular positions of the cam. Thus, the positioning device has a simplified construction in which the first and second engaging portions are provided in one and the other of the cam surface and the cam follower portion, whereby the braking apparatus can be manufactured at a reduced cost.
(5) A braking apparatus according to mode (4), wherein the first engaging portion and the second engaging portion are provided in the cam surface and the cam follower portion, respectively, wherein the first engaging portion consists of the plurality of engagers in the form of a plurality of engaging grooves formed in the cam surface and extending in parallel with the axis, and wherein the second engaging portion consists of an engaging projection formed in the cam follower portion and having a shape substantially corresponding to that of each of the engaging grooves.
Where the cam consists of a plate cam, the engaging grooves are easily formed in an outer circumferential surface of the plate cam. Further, since the engaging groove and projection are brought into contact with each other at their respective surfaces that are comparatively large, each of the engaging groove and projection does not suffer from a large amount of wear thereof, leading to a prolonged service life of the braking apparatus.
(6) A braking apparatus according to mode (3), wherein the operating member consists of an operating lever which is supported by the main body such that the operating lever is pivotable about a pivot axis thereof, wherein the positioning device includes an engaging protruded portion which is provided in one of the main body and the operating lever, and an engaging recessed portion which is provided in the other of the main body and the operating lever and which is engageable with the engaging protruded portion, and wherein one of the engaging protruded and recessed portions consists of a plurality of engagers which are selectively brought into engagement with the other of the engaging protruded and recessed portions, so that the movable member is held in one of the plurality of predetermined positions.
(7) A braking apparatus according to mode (3), wherein the operating member consists of an operating lever which is supported by the main body such that the operating lever is pivotable about a pivot axis thereof, wherein the positioning device includes an engaging protruded portion which is provided in one of the main body and a member pivotable together with the operating lever, and an engaging recessed portion which is provided in the other of the main body and the member pivotable together with the operating lever and which is engageable with the engaging protruded portion, and wherein one of the engaging protruded and recessed portions consists of a plurality of engagers which are selectively brought into engagement with the other of the engaging protruded and recessed portions, so that the movable member is held in one of the plurality of predetermined positions.
In the braking apparatus according to mode (6) or (7), the operating lever or the member pivotable together with the operating lever is prevented from being pivoted relative to the main body, by engagement of the engaging protruded and recessed portions, thereby preventing the rotation of the cam and accordingly the reverse movement of the movable member which is engaged with the cam.
(8) A braking apparatus according to mode (6), wherein the positioning device further includes an elastic member, and wherein the engaging. protruded and recessed portions are held in engagement with each other owing to an elastic force provided by the elastic member, so that the engagement is permitted to be released by elastic deformation of the elastic member which is caused when an amount of a force applied to the elastic member exceeds a predetermined threshold.
In the braking apparatus of this mode (8), the positioning device has a simplified construction as described above, in which the engaging protruded and recessed portions are brought into engagement and are released from the engagement in a so-called snap action manner, so that the user or operator of the vehicle can clearly recognize that the movable member has been positioned in one of the above-described plurality of predetermined positions relative to the main body. Further, the engagement of the protruded and recessed portions can be easily released by simply applying a force whose amount exceeds the predetermined threshold, to the elastic member.
(9) A braking apparatus according to mode (8), wherein the engaging recessed portion is provided by a plate spring which is bent, so that the engaging protruded portion (268) is permitted to be released from the engaging recessed portion by elastic deformation of the plate spring.
(10) A braking apparatus according to mode (9), wherein the operating lever includes a shaft portion having a circular shape in a transverse cross section thereof, and wherein the engaging protruded portion is provided by the shaft portion of the operating lever.
The arrangement according to this mode (10) eliminates a member exclusively used to serve as the engaging protruded portion, and accordingly contributes to simplification of the construction of the braking apparatus.
(11) A braking apparatus according to mode (6), wherein the positioning device further includes a biasing device, and wherein the engaging protruded portion consists of a protruded portion of a movable engaging member which is held by the one of the main body and the operating lever such that the movable engaging member is movable between a projected position and a retracted position thereof and is biased by the biasing device in a direction toward the projected portion away from the retracted position.
(12) A braking apparatus according to mode (3), wherein the positioning device includes:
a movable engaging member which is held by the operating member such that the movable engaging member is movable between a projected position and a retracted position thereof;
a switching device which is provided in the operating member, and which is operable to selectively establish a retraction permitting state in which the movable engaging member is permitted to be moved to the retracted position, and a retraction inhibiting state in which the movable engaging member is inhibited from being moved to the retracted position; and
a plurality of engaging recessed portions which are provided in respective portions of the main body, and which are selectively brought into engagement with a protruded portion of the movable engaging member when the movable engaging member is held in the projected position, for thereby holding the movable member in the selected one of the plurality of predetermined positions and inhibiting movement of the movable member relative to the main body from the selected position.
In this braking apparatus of this mode (12), the protruded portion of the movable engaging member is not disengaged from with the selected one of the engaging recessed portions, as long as the movable engaging member is held in its projected position by the switching device. Thus, the movable member is reliably held in the selected position relative to the main body, leading to an improved reliability in the operation of the braking apparatus.
(13) A braking apparatus according to mode (12), wherein the operating member consists of an operating lever which has an elongated tubular shape and which is pivotable about an pivot axis thereof that is perpendicular to an longitudinal direction thereof, and wherein the switching device includes:
an operating rod which is disposed within the operating lever such that the operating rod is movable in the longitudinal direction of the operating lever, between first and second longitudinal positions thereof which are closer to longitudinally distal and proximal end portions of the operating lever, respectively;
a biasing device which biases the operating rod toward the first longitudinal position away from the second longitudinal position;
an operating terminal portion which is provided in one of opposite end portions of the operating rod that is closer to the longitudinally distal end portion of the operating lever, and which is operable to move the operating rod toward the longitudinally proximal end portion away from the longitudinally distal end portion, against a biasing force provided by the biasing device; and
a working portion which is provided in the other of the opposite end portions of the operating rod, and which inhibits the movement of the movable engaging member toward the retracted position at least when the operating rod is held by the biasing force in the first longitudinal position, and permits the movement of the movable engaging member toward the retracted position when the operating rod is moved by the operation of the operating terminal portion, toward the second longitudinal position away from the first longitudinal position.
In the braking apparatus of this mode (13), the operating rod can be operated at its operating terminal portion by a hand of the user or operator of the vehicle which hand holds the operating lever, for placing the positioning device in its working state or non-working state. Thus, the reliability and maneuverability of the braking apparatus are further improved.
(14) A braking apparatus according to any one of modes (1)-(13), wherein the movable member is held by the main body such that the movable member is movable relative to the main body along a line that is perpendicular to the axis of the cam, and wherein the cam follower portion and the braking portion are held by a rear end portion and a front end portion of the movable member, respectively.
The movable member may be adapted to be pivoted, relative to the main body, about a pivot axis. However, where the movable member consists of a linearly movable member as defined in this mode (14), it is possible to further simplify the construction of the braking apparatus, or/and make the size of the braking apparatus more compact.
(15) A braking apparatus according to mode (14), wherein the cam consist of a plate cam, and wherein the cam surface is provided by an outer circumferential surface of the plate cam.
The cam may consist of any other kind of cam such as a groove cam in which a cam groove is formed in a surface perpendicular to its axis. However, where the cam consists of a plate cam as defined in this mode (15), its is possible to further simplify the construction of the apparatus and accordingly reduce the cost of manufacturing of the apparatus.
(16) A braking apparatus according to mode (15), wherein the movable member consists of a rod which is brought into sliding contact at a rear end portion thereof with the cam surface so that the rear end portion serves as the cam follower portion.
The arrangement defined in this mode (16) is effective to reduce the cost of the production of the cam follower portion.
(17) A braking apparatus according to mode (14), wherein the movable member consists of a rod, the braking apparatus further comprising a reverse-movement preventing device which prevents the movement of the rod in the reverse direction and which includes:
a pinch member including a first contact portion which is opposed to a first portion of an outer circumferential surface of the rod and which is spaced apart from the first portion by a predetermined distance, and a second contact portion which is opposed to a second portion of the outer circumferential surface of the rod that portion is opposite to the first portion and which is spaced apart from the second portion by a predetermined distance, the pinch member being held, at a portion thereof adjacent to one of the first and second contact portions, by the main body such that the pinch member is pivotable about an pivot axis thereof that is perpendicular to a longitudinal direction of the rod;
a torque applying device which applies a torque to the pinch member such that the pinch member is pivoted by the torque in such a direction that causes the first and second contact portions of the pinch member to be displaced in a direction toward the rear end portion of the movable member away from the front end portion of the movable member; and
a releasing device which is operable to pivot the pinch member against the torque applied by the torque applying device.
In the braking apparatus of this mode (17), the pinch member prevents the reverse movement of the rod from a desired position relative to the main body, whereby an amount of a pressing force, by which the braking member is pressed onto the tire of the wheel of the vehicle, can be held at a desired value, thereby further improving the maneuverability of the braking apparatus. It is noted that the releasing member may include a releasing lever which is disposed pivotably about its pivot axis that is not parallel with the longitudinal direction of the rod, and which is operable to be pivoted so as to pivot the pinch member.
(18) A braking apparatus according to mode (17), wherein the operating member consists of an operating lever which is pivotable about an pivot axis thereof, and wherein the releasing device includes:
a releasing lever which is disposed pivotably about a pivot axis that is not parallel with the longitudinal direction of the rod, and which is operable to be pivoted so as to pivot the pinch member;
a grip member which is disposed in a longitudinally distal end portion of the operating lever such that the grip member is movable relative to the operating lever in a longitudinal direction of the operating lever, and which is operable to be moved in the longitudinal direction, so as to be engaged with the releasing lever for thereby pivoting the releasing lever; and
a biasing device which is interposed between the grip member and the operating lever, and which biases the grip member in a direction away from the releasing lever.
In the braking apparatus of this mode (18), the releasing lever is pivoted by a simple operation in which the grip member is moved in the longitudinal direction of the operating lever against a biasing force of the biasing device, and an engagement of the pinch member with the rod is then released as a result of the pivot movement of the releasing lever. Thus, this arrangement is effective to further improve the maneuverability of the braking apparatus.
(19) A braking apparatus according to any one of modes (1)-(18), wherein the operating member consists of an operating lever which is attached at a longitudinal end portion thereof to the cam and is pivotable together with the cam about the axis of the cam.
In the braking apparatus of this mode (19), the cam can be rotated by operatively pivoting the operating lever, thereby simplifying the structure of the operating device and accordingly reducing the cost of production of the operating device.
(20) A braking apparatus according to mode (19), wherein the cam has a hole formed therein and extending in perpendicular to the axis of the cam, and wherein the longitudinal end portion of the operating lever is accommodated in the hole so that the operating lever is fixed to the cam.
In the braking apparatus of this mode (20), the operating lever is fixed to the cam, thereby further simplifying the structure of the operating device whereby the braking apparatus can be made more compact and accordingly manufacture at a further reduced cost. It is noted that the operating lever can be fixed to the cam, by any one of various manners, e.g., by press-fitting the longitudinal end portion of the operating lever into the hole of the cam, by bonding the end portion of the operating lever to the hole of the cam with a suitable welding, brazing or soldering, after introducing the end portion of the operating lever into the hole of the cam, or by screwing the end portion of the operating lever into the hole of the cam, after forming suitable threads in an outer circumferential surface of the end portion of the operating lever and in an inner circumferential surface of the hole of the cam.
(21) A braking apparatus for braking a wheel of a vehicle, comprising:
a main body;
a movable member which is held by the main body such that the movable member is movable relative to the main body, and which includes a braking portion brought into contact with a tire of the wheel; and
an operating device which includes an operating member, and which is operable to move the braking portion toward and away from the tire of the wheel in response to an operation of the operating member.
Each of the braking apparatuses according to respective modes (21)-(33) may include the technical feature according to any one of the above-described modes (1)-(20), so that the braking apparatus enjoys further improved maneuverability and durability.
(22) A braking apparatus according to any one of modes (1)-(21), wherein the braking portion includes:
a braking member which is rotatable about an axis thereof; and
a reverse-rotation inhibiting device which inhibits rotation of the braking member in one of opposite directions while permitting rotation of the braking member in the other of the opposite directions.
In the braking apparatus of this mode (22), the reverse-rotation inhibiting device inhibits the rotation of the braking member in the above-described one of the opposite directions and permits the rotation of the braking member in the other of the opposite directions, for thereby inhibiting a reverse rotation of the wheel that would cause the vehicle to move in its forward direction and permitting a forward rotation of the wheel that causes the vehicle to move in its rearward direction, while the braking member is held into contact with the tire of the wheel. Where the axis of the braking member is disposed in substantially parallel to an axis of the wheel, the rotation of the braking member in the above-described one of the opposite directions is interpreted to correspond to the rotation of the braking member in such a direction that causes a contact portion at which the braking member is brought into contact with the tire of the wheel, to be moved in the same direction in that a contact portion of the tire, which is brought into contact with the braking member, is moved during the reverse rotation of the wheel. The rotation of the braking member in the above-described other of the opposite directions, on the other hand, is interpreted to correspond to the rotation of the braking ember in such a direction that causes the contact portion of the braking member to be moved in the same direction in that the contact portion of the tire is moved during the forward rotation of the wheel.
Although the braking member whose rotation in the above-described one of the opposite directions is not inhibited by the braking-member-rotation inhibiting member does not inhibit the forward rotation of the wheel, the braking member applies a resistance to the forward rotation of the wheel while the braking member is pressed against the tire by a pressing force so large that the contact portion of the tire is radially inwardly deformed. The amount of the resistance to the forward rotation of the wheel increases with an increase in the amount of the pressing force by which the braking member is pressed against the tire. Thus, the braking apparatus of this mode (22) is capable of generating a suitable amount of braking force, particularly, when the vehicle is moving in a downslope. Further, the braking member does not practically slide on the tire since the braking member is rotated during the forward rotation of the wheel, leading to a reduction in the amount of wear of each of the braking member and the tire and consequently improving durability of each of the braking member and the tire.
(23) A braking apparatus according to mode (22), further comprising a rotation-resistance applying device which applies a resistance to the rotation of the braking member in the other of the opposite directions.
In the braking apparatus of this mode (23), the resistance acting against the forward rotation of the wheel is increased by an amount corresponding to the amount of the resistance applied to the rotation of the braking member by the rotation-resistance applying device. The increase in the amount of the resistance to the forward rotation of the wheel makes it possible to sufficiently brake the wheel, even without a large amount of the radially inward deformation of the contact portion of the tire during braking of the wheel. Where the wheel requires to be slightly braked while the amount of the resistance applied to the braking member by the braking-member-rotation-resistance applying member is held substantially constant, the braking member is held in sliding contact with the tire without rotation of the braking member, by reducing the pressing force by which the braking member is pressed onto the tire. In this instance, since the pressing force is reduced, there is not generate a large amount of friction force between the braking member and the tire, thereby preventing a large amount of wear of each of the braking member and the tire.
(24) A braking apparatus according to mode (23), wherein the rotation-resistance applying device constitutes a part of the reverse-rotation inhibiting device, so that the reverse-rotation inhibiting device applies the resistance to the rotation of the braking member in the other of the opposite directions although permitting the rotation of the braking member in the other of the opposite directions.
The rotation-resistance applying device may includes a resistance applying member which is brought into contact with a portion of the braking member that is other than the contact portion of the braking member that is brought into contact with the tire of the wheel such that a friction force acting between the resistance applying member and the braking member is smaller than the friction force acting between the braking member and the tire of the wheel. Further, the reverse-rotation inhibiting device may constitute a part of the rotation-resistance applying device, for thereby making it possible to further simplify the construction of the braking apparatus and accordingly reducing the cost of manufacturing of the braking apparatus.
(25) A braking apparatus according to mode (23) or (24), wherein an amount of the resistance applied by the rotation-resistance applying device to the rotation of the braking member increases with an increase of an amount of a pressing force by which the braking member is pressed onto the tire of the wheel.
(26) A braking apparatus according to mode (25), wherein the rotation-resistance applying device includes a resistance applying member which is brought into pressing contact with the baking member by a reaction force applied from the tire to the braking member when the braking member is pressed onto the tire.
In the braking apparatus of this mode (26), the resistance applied from the resistance applying member to the rotation of the braking member increases with an increase in the pressing force by which the braking member is pressed against the tire of the wheel. The resistance applied from the resistance applying member to the rotation of the braking member may be made smaller than a rotary driving force applied from the wheel to the braking member, for thereby making it possible to apply a resistance to the rotation of the wheel so as to brake the wheel, while preventing sliding movement or reducing an amount of the sliding movement of the braking member and the wheel relative to each other. It is noted that the resistance applying member may be adapted to be brought into pressing contact with a portion of the braking member which portion is other than the above-described contact portion at which the braking member is brought into contact with the tire of the wheel.
(27) A braking apparatus according to mode (26), wherein the braking portion includes:
a pivoting member which is held by the movable member such that the pivoting member is pivotable about a pivot axis thereof that is substantially parallel to an axis of the wheel of the vehicle so as to be moved between first and second pivot position thereof, and which holds the braking member in a distal end portion thereof; and
a biasing device which biases the pivoting member in such a direction that causes the braking member to be brought into contact with the tire of the wheel;
and wherein the movable member is positionable in a reverse-rotation inhibiting position for establishing a reverse-rotation inhibiting state in which the braking member is brought into contact with the tire by a biasing force of the biasing device when the wheel is rotated in a forward direction thereof and in which the pivoting member is moved to the first pivot position so as to cause the braking member to bite into the tire for thereby inhibiting reverse rotation of the wheel when the wheel is about to be rotated in a reverse direction, and in a forward-rotation braking position for establishing a forward-rotation braking state in which the pivoting member is moved to the second pivot position against the biasing force of the biasing device for permitting the braking member to be brought into pressing contact with the resistance applying member.
(28) A braking apparatus according to any one of modes (1)-(27), wherein the braking portion includes:
a braking member which is brought into contact with the tire of the wheel;
an attaching device through which the braking member is attached to the movable member such that the braking member is movable relative to the movable member over a predetermined distance toward and away from the wheel; and
a biasing device which biases the braking member in such a direction that causes the braking member to be moved relative to the movable member toward the wheel.
In the braking apparatus of this mode (28), even if the movable member is slightly displaced relative to the main body, the braking member keeps to be forced onto the tire of the wheel by a biasing force provided by the biasing device, whereby the braking apparatus is reliably held in its working state, and accordingly the maneuverability and reliability of the braking apparatus are further improved.
(29) A braking apparatus according to mode (28), wherein the attaching device includes a slide which is fitted on the movable member such that the slide is slidably movable relative to the movable member, and a defining device which defines a maximum distance over which the slide can be moved relative to the movable member.
(30) A braking apparatus according to any one of modes (1)-(29), wherein the braking portion includes:
a braking member which is brought into contact with the tire of the wheel;
a pivoting member which is held by the movable member such that the pivoting member is pivotable about a pivot axis thereof that is substantially parallel to an axis of the wheel of the vehicle so as to be moved between first and second pivot position thereof, and which holds the braking member in a distal end portion thereof; and
a biasing device which biases the pivoting member in such a direction that causes the braking member to be brought into contact with the tire of the wheel;
and wherein the movable member is positionable in a reverse-rotation inhibiting position for establishing a reverse-rotation inhibiting state in which the braking member is brought into contact with the tire by a biasing force of the biasing device when the wheel is rotated in a forward direction thereof, and in which the pivoting member is moved to the first pivot position so as to cause the braking member to bite into the tire for thereby inhibiting reverse rotation of the wheel when the wheel is about to be rotated in a reverse direction.
In the braking apparatus of this mode (30), the reverse rotation of the wheel is reliably prevented while the movable member is positioned in the reverse-rotation inhibiting position. The vehicle, which is equipped with the present braking apparatus whose maneuverability is thus improved, is prevented from being moved in the reverse direction, even if the operating member and the wheel are released by the user during movement of the vehicle on an upslope.
(31) A braking apparatus according to mode (30), wherein the biasing device biases the pivoting member in such a direction that causes the pivoting member to be moved toward the first pivot position.
(32) A braking apparatus according to mode (30), wherein the biasing device biases the pivoting member in such a direction that causes the pivoting member to be moved toward the tire of the wheel.
(33) A braking apparatus according to any one of modes (21)-(32), wherein the braking portion includes:
a braking member which is rotatable about an axis thereof and which has an outer circumferential surface that is brought into pressing contact with the tire of the wheel.
Where the braking member is permitted to be rotated in the opposite directions, it is possible to adapt the braking apparatus to apply a desired amount of braking force to the wheel not only during the forward movement of the vehicle but also during the reverse movement of the vehicle.